DNA40 efficiency

[Baba Fats]

I apologize if this has been beaten to death, but I am looking for some answers on what dual battery configuration is supposed to be more efficient.

I'm looking specifically at regulated mods...

I have both a Vapor Flask DNA40, and Sigelei 150TC. The VF is parallel, and the Sig is Series. I know that the DNA40 chip is already more efficient, so that explains my confusion a little, but I've come across tons of articles and posts that say batteries in series are supposedly more efficient. The explanations make sense. But it doesn't explain why I need to swap out batteries in my Sigelei twice a day, and I can get 2 full days out of my VF before needing to recharge.

I vape the same tanks, with the same coils, and at the same wattage on both mods, and I always notice how much better the VF does on batter life. Can anyone offer me a more in depth explanation other than the evolve chip being that much more batter efficient?

 

[DED420]

Series = Double the Voltage
Parallel = Double the Amps/mAh

Series is more efficient at pushing higher power levels.
Parallel is more efficient on your batteries.
Running the same coil at the same setting, the only difference you'll experience is with battery length.

You'd only start noticing the differences once you start to build lower ohm coils at higher Wattages, and actually putting the cells to work.
Since both are regulated mods, the chips handle the buck/boost levels, and convert the Voltage/Amperage accordingly.

You're using a build and power levels that can be achieved through a single cell 18650 with ease (the VF is a 40W mod, 18650 are capable of a true 75W, so you're not making the cells work hard at all).

Here's a hypothetical example, numbers are not accurate in any way (assume all are unregulated mechs)

*For this example, we'll use one minute as our value for mAh*

You have one mod, capable of putting out 10A for 1 minute at 4.2V.
You have another mod also capable of putting out 10A for 1 minute at 4.2V.
You have a coil that only draws 10A at 4.2V, per minute.

Now you place another battery in mod 1 in Parallel.
This mod is now capable of 20A at 4.2V for 2 minutes.

Place another battery in mod 2 in series.
This mod is now capable of 10A at 8.4V for 1 minute.

Volts are equal to how much power the batteries can force through the coil.
Amps are equal to how easily the batteries can produce/release that power.

Although these configurations have now increased the power capabilities, the resistance has stayed the same, meaning that the coil isn't drawing any more power than it was. Since the coil isn't making use of the extra Volts or Amps, there is no change in power consumption. But the Parallel mod now has double the mAh (battery capacity), thereby doubling the batteries run-times.


That was quite a bit harder to explain than I thought it would be, and I certainly hope that it makes sense.

 

[Baba Fats]

That was actually perfect. The last paragraph summed it up great. I don't have much interest in vaping that far sub ohm. I typically use coils at 1-1.3 ohms. Once in a while I drip at 0.5 ohms, and occasionally I use nickel coils at 0.12-0.15 ohms. I haven;t gotten into Ti, or SS yet. And my DNA40 can only handle Ni. Not sure about my sig or sx mini. But I bought them for the quality of the chip rather than functions

 

[Baba Fats]

Out of curiosity, when you say that series is more efficient at higher power, how high? I typically don't go above 14 watts, so parallel is better for me there, but sometimes I do hit the 30-40 watt range.

I just don't see myself ever vaping higher than that.

 

[DED420]

Yeah, I'm talking about the 80W+ range, if you only intend to go to 40W max, then parallel is the better route for you.
A general rule of thumb is that 18650's are capable of a true 75W per cell, so anything above will be "boosted" by the chip (drawing higher Volts to achieve the Wattage). So, 100W on a 0.25Ω coil at 20A will need 5V (which a single 18650 can't provide) so stacking them in series gives you the extra Voltage needed to achieve the 100W without "boosting".

I'll leave this link here if you want to read deeper into how it actually does that, it's far too technical for me to try and explain coherently: https://en.wikipedia.org/wiki/Boost_converter

 

[Baba Fats]

Gotcha. Yeah, I don't plan to venture into that range often, if ever. IfI ever do, I've got my Sig 150tc for that. Otherwise I'll stick with my vapor flask. As much as I've started to like the layout of the yihi menu, the DNA boards are so much more efficient. And the v5 board is just as reliable and accurate as my sx mini